The present invention is directed to a gas turbine engine with increased fuel efficiency, and more specifically, to a gas turbine engine having a second combustion chamber that receives high pressure gas from the compressor and to a method for increasing the efficiency of the engine.
Gas turbine engines are well-known and are mostly noted for their use in aircraft. Gas turbines are heat engines that use air as a working medium and mechanical shaft horsepower to generate a propulsive force called thrust. In atypical gas turbine engine, atmospheric air is drawn into the engine by a fan disposed at its inlet. A primary portion of the air received by the inlet is passed through a core portion of the engine while a secondary portion of the inlet air passed through a bypass duct surrounding the core portion of the engine to cool the engine.
The primary portion of air received by the core engine is passed through a series of compressors, where it is compressed. The compressors are driven by a pair of co-axial shafts connected to a series of turbines displaced downstream of the compressors. A combustion chamber positioned downstream of the compressors and upstream of the turbines receives the compressed air and fuel. In the combustion chamber, the air is mixed with the fuel, creating an air-fuel mixture that is ignited to generate exhaust gases having high energy. The exhausts gases are then passed and partially expanded through a series turbines that convert the exhaust gases""s high pressure energy into mechanical energy to drive the co-axial shafts driving the compressors upstream. The exhausted gases generated by the engine core portion are joined with the air passed by the engine core portion and are then accelerated as they pass through an exhaust nozzle located downstream of the turbines. These gases are then exhausted from the exhaust nozzle into the atmosphere in the form of thrust. Consequently, as the speed of the ambient air entering the inlet increases, the thrust generated by the engine also increases.
Performance of gas turbine engines are largely based on the amount of thrust the engines generate in comparison to their weight (thrust-to-weight ratio), as well as the amount of fuel the engine consumes. Due to the rising cost of fuel there is a need for an improved engine that efficiently uses the high pressure energy generated by the compressors to provide increased thrust, while requiring less fuel consumption.
The present invention is an improved fuel efficient gas turbine engine and method of accomplishing the same, increasing the fuel efficiency of gas turbine engines. Gas turbine engines, constructed according to principles of this invention, generally comprise a primary combustion chamber for receiving a primary portion of high pressure air passing from a high pressure compressor, and a secondary combustion chamber for receiving a secondary portion of high pressure air passing from the high pressure compressor. The primary combustion chamber is configured such that it passes exhaust gases to drive high and low pressure turbines located downstream of the primary combustion chamber. The secondary combustion chamber is configured to pass exhaust gases to only drive the low pressure turbine. A mechanical controller is provided to control the amount of high pressure air passing into the secondary combustion chamber.
The mechanical controller consists of a central control unit and a manual fluid pressure control unit that is coupled to a top portion of the central control unit. The central control unit is generally constructed as a box having a fluid reservoir and a piston well disposed within its interior. The fluid reservoir is constructed to receive fuel passing from a high pressure fuel line connected to a base portion of the box. The high pressure fuel confined in the fluid reservoir generates in pressure forces within the box""s interior. The piston well is constructed in communication with the fluid reservoir and confines a piston that translates under the influence of the pressure forces between a first position and a second position. The piston is coupled to a linkage that actuates a slider positioned at an inlet to the secondary combustion chamber. The slider moves in response to the translation of the piston to block or unblock the inlet, varying the amount of high pressure air passing into the secondary combustion chamber.